This invention is related to a balloon dilation catheter for angioplasty procedures, particularly in peripheral arteries.
Angioplasty procedures generally involve advancing a dilatation catheter with an inflatable inelastic balloon on the distal portion through a patient's vasculature until the balloon crosses a stenotic region. Inflation fluid is introduced into an inner lumen of the catheter at the proximal end thereof to inflate the balloon and thereby dilate the stenosis. Usually, a guidewire is first advanced through the patient's arteries until the distal tip thereof passes through the stenotic region. The dilatation catheter is then advanced over the guidewire until the balloon is in its proper position for stenotic dilatation. This procedure is used both in coronary arteries and in peripheral arteries. The former is called percutaneous transluminal coronary angioplasty (PTCA) and the latter merely percutaneous transluminal angioplasty (PTA).
Dilatation catheter for angioplasty procedures with fixed guidewires or guiding elements have been used with greater frequency because such catheters generally have lower profiles and have better pushing characteristics which facilitate advancing through the patient's vasculature.
Further details of dilatation catheters, guidewires and associated accessories for angioplasty procedures are described in the following U. S. Patents which are incorporated herein in their entirety.
______________________________________ 4,323,071 Simpson-Robert 4,538,622 Samson et al. 4,332,254 Lundquist 4,439,185 Lundquist 4,554,929 Samson et al. 4,468,224 Enzmann et al. 4,582,181 Samson 4,516,972 Samson 4,616,652 Simpson 4,538,622 Samson et al. 4,619,263 Frisbie et al. 4,619,274 Morrison 4,641,654 Samson et al. 4,664,113 Frisbie et al. 4,721,117 Mar et al. ______________________________________
While the dilatation catheters and guidewires for peripheral arteries are very similar to dilatation catheters for coronary arteries, there are significant differences due to the nature of the arteries being treated. Generally, the catheters for peripheral arteries have much larger diameters and have a greater degree of pushability than catheters for coronary use. Additionally, for example, only a small distal portion, i.e., the last 30 cm, of a dilatation catheter for coronary arteries will pass through tortuous arterial passageways whereas most of a dilatation catheter for peripheral arteries will pass through tortuous passageways. Thus the catheter and guidewire for peripheral artery use needs to be longitudinally flexible over essentially the entire length thereof which is introduced into the patient. However, increasing the longitudinal flexibility usually entails a loss in the pushability of the catheter. What has been needed is a dilatation catheter with enhanced flexibility and pushability to more readily be advanced through severe tortuous arterial passageways. The present invention satisfies that need.